1. Field of the Invention
The invention concerns a device for placing a paper bag bottom that has connected and glued folded bottoms.
2. Description of the Prior Art
Devices of this kind are used for manufacturing different types of bags. These include cement bags that are usually manufactured as valve bags. For this purpose usually the bottom folding involves the use of valve sheets that are inserted in the bottom of the bag. However it is important to differentiate between pinch-, block- and cross bottoms. In the creation of cross bottom bags that is explained, for instance, in DE 090 145 48 U1 and DE 3020043 A1, special demands were placed on the gluing.
In all devices of this kind the bag bottoms are formed with the help of glue—usually starch glue. For this purpose either the folded bottoms or the valve sheets assigned to them or both the aforementioned elements to be glued are provided with a glue layer and subsequently merged together. Each of the bag components is glued usually by bringing a format part in contact with glue rollers or other glue storage or transmission components. The format part is attached to a rotating roller and is often also referred to as a plate. By rotating the glue roller, the format part is supplied with glue. As the glue roller continues to rotate, the format plate transfers the glue stored on it to the respective bag component to be glued.
For this purpose the format part is provided with characteristic peaks (ridges) that are adapted to a definite bag format. In order to manufacture bags with different measurements on the bottoming device the format parts are replaced.
The described type of glue application has stood the test of time in the devices for placing a paper bag bottom because it enables a clean application of large quantities of starch glue that is otherwise difficult to handle.
However, this method of glue transfer makes it necessary to make available and later clean many mechanical glue transfer components—such as for instance the plate roller and the format parts.
Therefore the task underlying the present invention is to make these components redundant.